This relates, in general, to semiconductor devices; and, more specifically, to programmable circuits and their methods of manufacture.
The programming of integrated circuits and similar semiconductor devices often relies on the use of fuses as a programming component. To program an integrated circuit device, fuses in the circuit can be selectively left intact, or opened, to create circuit paths according to a predefined design. Fuses can thereby be used to implement a variety of programming functions.
One problem with the use of conventional fuses, however, is that the size of fuses have not been scaled down as rapidly as the size of transistors. This can be problematic in devices that incorporate thousands of fuses to implement increasingly sophisticated circuit programming. That is, the size of fuses can limit the extent of miniaturization of semiconductor devices. Another problem is that only a binary signal information is obtained from a fuse (e.g., a zero or non-zero current). Consequently, to send more complex control signals, several fuses have to be used, thereby increasing the amount of space on a circuit that is occupied by fuses.